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b6a02c3606
1. Refactor files so that all implementations are in the multiarch
directory
- Moved the implementation portion of memmove sse2 from memmove.S
to multiarch/memmove-sse2.S
- The non-multiarch file now only includes one of the
implementations in the multiarch directory based on the compiled
ISA level (only used for non-multiarch builds. Otherwise we go
through the ifunc selector).
2. Add ISA level build guards to different implementations.
- I.e memmove-avx2-unaligned-erms.S which is ISA level 3 will only
build if compiled ISA level <= 3. Otherwise there is no reason
to include it as we will always use one of the ISA level 4
implementations (memmove-evex-unaligned-erms.S).
3. Add new multiarch/rtld-memmove.S that just include the
non-multiarch memmove.S which will in turn select the best
implementation based on the compiled ISA level.
4. Refactor the ifunc selector and ifunc implementation list to use
the ISA level aware wrapper macros that allow functions below the
compiled ISA level (with a guranteed replacement) to be skipped.
Tested with and without multiarch on x86_64 for ISA levels:
{generic, x86-64-v2, x86-64-v3, x86-64-v4}
And m32 with and without multiarch.
isa raising memmove
118 lines
3.8 KiB
C
118 lines
3.8 KiB
C
/* Common definition for memcpy, mempcpy and memmove implementation.
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All versions must be listed in ifunc-impl-list.c.
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Copyright (C) 2017-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <init-arch.h>
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extern __typeof (REDIRECT_NAME) OPTIMIZE (erms) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned_erms)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_no_vzeroupper)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned_erms)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx_unaligned) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx_unaligned_erms)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx_unaligned_rtm)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (avx_unaligned_erms_rtm)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned)
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attribute_hidden;
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extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned_erms)
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attribute_hidden;
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static inline void *
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IFUNC_SELECTOR (void)
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{
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const struct cpu_features *cpu_features = __get_cpu_features ();
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if (CPU_FEATURES_ARCH_P (cpu_features, Prefer_ERMS)
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|| CPU_FEATURES_ARCH_P (cpu_features, Prefer_FSRM))
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return OPTIMIZE (erms);
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
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&& !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
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{
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
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{
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if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
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return OPTIMIZE (avx512_unaligned_erms);
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return OPTIMIZE (avx512_unaligned);
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}
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return OPTIMIZE (avx512_no_vzeroupper);
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}
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if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
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AVX_Fast_Unaligned_Load, ))
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{
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
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{
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if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
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return OPTIMIZE (evex_unaligned_erms);
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return OPTIMIZE (evex_unaligned);
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}
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if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
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{
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if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
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return OPTIMIZE (avx_unaligned_erms_rtm);
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return OPTIMIZE (avx_unaligned_rtm);
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}
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if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
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Prefer_No_VZEROUPPER, !))
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{
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if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
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return OPTIMIZE (avx_unaligned_erms);
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return OPTIMIZE (avx_unaligned);
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}
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}
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if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
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/* Leave this as runtime check. The SSSE3 is optimized almost
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exclusively for avoiding unaligned memory access during the
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copy and by and large is not better than the sse2
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implementation as a general purpose memmove. */
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&& !CPU_FEATURES_ARCH_P (cpu_features, Fast_Unaligned_Copy))
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{
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return OPTIMIZE (ssse3);
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}
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if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
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return OPTIMIZE (sse2_unaligned_erms);
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return OPTIMIZE (sse2_unaligned);
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}
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